A) Ancient Times
Democritus didn't think that Aristotle was right. He thought matter was made out of atoms. He called them atomos. Atomos meant "indivisible". Unfortunately, Democritus was born in a small town. Because of this, people didn't believe him. His ideas were ignored.
B) Alchemists
Roger Bacon was an English alchemist that may or may not have been the first european to invent gunpowder. Some people think differently, like it was a german guy or the chinese hundreds of years ago.
Alchemists work was mostly try to turn (something) into gold. This was called a "trasmutation" reaction, but it couln't be done with chemical reactions. Althogh, they did discover some chemistry.
The ancient Egyptians, on the other hand, were practical and invented lots of things. They made the first glass, and dyes and medicines.
Alchemy:
•The Greeks called this “chemia,” after the Egyptian word “Chem,” which meant "black". "Chem" was the Egyptian name for their own country. Some people thought that "chemia" meant "black magic" because some Egyptian prosesses looked like magic. When the Arabs conquered Egypt, the prefix "al", which meant "the", was added to the word "chemia", so it became "alchemia".
After that, in English it became "alchemy". This name was much better because before, alchemy wasn't considered a real, or important science.
17th and 18th century
He was a British nobleman (the youngest of 14 children born to the Earl of Cork). He was an alchemist so he met GalilEo. Maybe the last alchemist and the first one to be A real scientist.
He invented a vacuum pump, did experiments with gases, & is credited with "Boyle's Law": P1 x V1 = P2 x V2
This. Law states that pressure and volume are “inversely proportional”. This means that if pressure goes up, volume goes down and vice versa.
He called himself a "chymist" because the name "alchemist" was considered now as a bad name.
He questioned the Greek notions of the elements. He discovered that water, considered an element, wasn't a element, but a compound.
By 1700, 14 elements were known, by the end of the 1700s, 11 more were known.
Chemistry evolved a lot in that time, but most chemists didn't pay attention to the quantitative aspects of chemistry. Saw, but didn't measure. In the late 1700s, a French chemist changed all that, but first...
Josefh priestley was the main supporter of a theory: phlogiston. But he also created something much more intresting: carbonated drinks or, specifically, soda water.
Here's a video that Can explain to you what and how the phogiston is and works.
He was called the Father of Modern Chemistry
He also Proved that air was composed of 1/5 oxygen and 4/5 nitrogen
He Proved that hydrogen and oxygen combine to form water, proving at last that water was a compound.
And finally he Demonstrated experimentally the principle renamed "the law of conservation of mass".
Dalton was a quaker schoolmasterthat studied every science, but focused mostly in chemistry. He developed the atomic theory and the law of multiple proportions. The atomic theory helped many scientists to explain their observations. The law of multiple proportions helped explain that 2 elements could combine and form 1 or morecompounds; an example co & co2.
The Atomic Theory
1. All elements are composed of tiny indivisible particles called atoms.
2. Atoms of the same element are identical. The atoms of any one element are different from those of other elements.
3. Atoms of different elements can chemically combine with one another in small whole-number ratios to form compounds.
4. Chemical reactions occur when atoms are separated, joined or rearranged. Atoms of one element cannot be changed into atoms of another element by chemical rxns.
